The present invention is directed toward a tong arm assembly and more particularly toward such a device which is not subject to wear and which, therefore, is capable of positively maintaining the orientation of glass bottles without rocking as they are being moved from molds to a conveyer belt.
Tong arm assemblies or take-out assemblies as they are sometimes called are well known in the glass forming art. These devices are utilized in automatic bottle forming machines to arcuately move a tong head assembly between a first position overlying the glass forming molds and a second position horizontally remote therefrom overlying a conveyer belt. The tong arm assembly carries a tong head such as described in U.S. Pat. No. 4,185,985. As is well known in the art, the tong head carries one or more tong holders and tongs which pick up the formed bottles or other glassware to move the same from the molds to the conveyer belt.
In order to prevent breaking of the finished bottles, it is very important to strictly maintain the orientation of the bottles in their upright vertical position while they are being moved from the molds to the conveyer belt. This, of course, can only be done if the movement and orientation of the tong head assembly is positively and accurately controlled.
Attempts have been made in the past to provide a tong arm assembly which would positively control the movement of the tong head. A tong arm assembly is shown, for example, in U.S. Pat. No. 3,095,082 and particularly in FIGS. 5 and 6 thereof. This assembly includes a first sprocket mounted on the shaft about which the assembly rotates and a second sprocket remote therefrom and connected to the tong head. A continuous chain interconnects the sprockets so that the two sprockets are forced to move in unison with each other so as to maintain the proper orientation of the tong head.
Unfortunately, after a period of time it has been found that the chains tend to wear as do the sprockets in the area where the chain and sprockets continuously engage and disengage each other. As a result of this wearing effect, there is some minor freedom of movement in the tong head which causes the same to rock thereby resulting in checked or broken bottles. And while devices such as shown in U.S. Pat. No. 3,095,082 have been devised for compensating for the wear of the chain and sprockets, this requires additional and continuous adjustments and eventually the chain and/or sprockets must be replaced.
Another attempt at positively driving the tong head has been the use of a plurality of gears in place of the chain and sprockets. Examples of such gear arm assemblies are shown in U.S. Pat. Nos. 1,859,956 and 3,410,417. In these arrangements, the two sprockets are replaced by gears and an additional idler gear is mounted there between. Unfortunately, this arrangement has also not been totally satisfactory since eventually the gears tend to wear as they mesh again causing the tong head assembly to rock slightly which eventually results in the breaking of the glassware being moved from the molds to the conveyer belt.